'Ere John, wanna new motor?: James Ruppert has some advice on how to get the best deal for your wheels

Any idiot can buy a car. New, or used, you simply pay your money and you make a - possibly ill-informed - choice. However, turning your car back into cash again is not always so easy.

In London, the chances of liquidising your automotive asset are high. After all, the capital is the largest used-car market in Europe and someone, somewhere must want your car - it is just a matter of finding out who.

Traditionally, the most common way to shift your motoring wares is by advertising. You simply write the ad and wait for the phone to ring, right? Well, wrong actually, because the right car has to go into the right publication and, believe it or not, there is an art to writing used car classified ads.

First, don't be long-winded, you are paying for every word. Most people state the obvious: the 'Ford' in Ford Escort is superfluous because those looking for an Escort already know that it is made by Ford. Just stick to the facts: model, mileage, whether it is taxed and tested (use the abbreviation t&t), and the price - compare your car with similar models advertised locally and make it competitive.

The advertisement should appear in an appropriate publication. Your local paper is good start, especially for cheaper vehicles. London-wide, there are several regional editions of Auto Trader which charge pounds 17 for a picture and 27-word description, a good place to put anything from bargain to prestige cars.

If you are mean, though, Loot and the London Weekly Advertiser offer a free advertisement service. Loot's 'On the Road' section is far more comprehensive and better laid-out than the 'Car Finder' in the Advertiser. Let's also blow our own Independent London trumpet here, because you can take out a free car ad on the page opposite.

If you have a heap without an MoT clogging up your drive or garage don't despair, there is a scrap dealer or dismantler near you willing to tow the offending eyesore away and pay you for the privilege. How much you are paid depends on the desirability of the car. The minimum is usually pounds 10, while many will pay around pounds 25, as a basic scrap value. It is best to phone around first.

Alternatively you could break the car yourself. Auto Trader allows free advertisements for items up to pounds 300. A workshop manual will guide you through the dismantling process.

Auctions are a relatively easy way to unload your car but not always profitable, especially if you have only a cheap banger. Much depends on the car itself, but you will essentially get a trade price for the vehicle, and at least the deal is done quickly.

Whitechapel Car Auctions charges a pounds 23 entry fee and a 10 per cent commission on the sale price to a minimum of pounds 50, plus pounds 6 sundries and VAT. If you put a reserve price on the car and if fails to reach that figure, any subsequent entry costs a further pounds 23.

Fancy swimming in the shark-filled waters of the motor trade? Dip your toes in by offering your pride and joy to a jobbing car trader, or dealer. What they pay is a trade price. Be warned that this figure will always be much less than you think. The advantage of selling this way is that their decision is almost instant and so is the money, usually cash.

There are lots of 'Cars Wanted' advertisements in your local paper, so get a reaction and a rough price by phoning around. If you have a desirable town car, off-roader or convertible that has been well looked after, your local new car franchise may be interested, and could pay a fair price too. Value-guide booklets available from newsagents should give you a fair idea of what the trade will pay.

Agency selling also takes the hassle out of selling the car to a fussy member of the public. If you have a nice motor, especially a classic, many car dealers won't hesitate to stick your car on their forecourt and collect a commission, or fee on sale. However, ensure that the dealer is established (ie, won't go bankrupt) and agree terms, especially insurance liability, before letting anyone have the car.

The good old cardboard sign in the window reading 'For Sale' can also work, but the car has to be parked where it will be seen. Leave it outside your house and only your neighbours will see it. Main roads are the best places, where thousands of reluctant pedestrians and drivers in need of a change will pass by, then hopefully double back for a closer look.

However, what works best is rather cheekily leaving the car near proper car lots. Some pedestrians or motorists will be in that area specifically because they want to buy a car. Otherwise, this cheap and cheerful approach is one that relies on chance.

Some handy tips:

Do clean the car. A neat and tidy vehicle creates a good impression and increases its value.

Be suspicious of everyone; London is a dangerous place.

Ensure that a friend is with you at all times during the sales process.

Be realistic about the value of your car.

Don't ever let your car out of sight before it has been paid for in cash, or with cleared funds.

Let a potential buyer drive the car on their own or without checking that they have a driver's licence and insurance.

Make any promises about the car's mileage, history, or reliability unless you have full documentary proof to support any claims.

(Photograph omitted)